1. Field of the Invention
This invention is used in the technical field of a floor polisher, a buffing machine or a burnisher (hereinafter simply referred to as "floor polisher") for effectively performing a floor buffing or polishing as the last stage of a floor dry care system and more particularly to a floor polisher equipped with a device for collecting various dusts which are generated when a buffing pad is rotated at a high speed for buffing a floor.
2. Brief Description of the Prior Art
In general, in order to polish up a floor using a floor polisher, a floor polisher of the type as shown in FIG. 5 is used after various waxes are applied to a floor.
That is, FIG. 5 illustrates a sectional view of an important portion of a conventional floor polisher. In the figure, reference numeral 1 denotes a motor, 2 denotes a hub directly connected to the motor 1, 3 denotes a pad table mounted on the hub 2, and 4 denotes a buffing pad mounted on the bottom surface of the pad table 3 by a center lock 5. Similarly, 3a denotes a coarse brush-like fiber bonded to the floor surface of the pad table 3. The burnishing pad 4 is made of a nonwoven fabric formed with polishing materials mixed and bonded together and is centered by the center lock 5. Such burnishing pad 4 is cut into the fiber 3a and mounted on the bottom of pad table 3. The burnishing pad 4 is rotated by the motor 1 at a high speed such as, for example, .phi.510 mm, 2,000 rpm and 52 m/sec of a peripheral speed.
However, when the above-described conventional floor polisher is used, various dusts such as wax powders, polishing materials and fiber odds of the pad, cotton odds, hairs, or earth and sand (hereinafter simply referred to as "dust") remaining on the floor are scattered around by a circulation air current caused by the buffing pad 4 which rotates at a high speed and make dirty the indoor environment, merchandise and the like, or equipment and the like.
As a counter-measure, the buffing pad 4 is covered at the upper surface side thereof with a cover member 6, a skirt 7, etc. as shown in FIG. 5 in order to prevent the scattering of the various dusts. However, this method is not effective when a floor F has an uneven surface because gaps are formed between the floor and the skirt and dusts are scattered outside through the gaps to make the floor therearound dirty.
That is, an air current generated by the buffing pad 4 rotating at a high speed circulates at a high speed through an internal space 8 between the buffing pad 4 and the skirt 7 of FIG. 5 in the direction as shown by the broken-line arrows X in FIG. 6. Since there are two speed components, i.e., one is in the circumferential direction and the other in the radius direction, the circulating speed is slowed down to some extent. However, if gaps are formed between the floor F and the skirt 7 when the cover member 6 and the motor 1 are completely sealed, a dust-containing air current is jetted out through the gaps as shown by big arrows A and the same amount of atomsphere as that of the jetted air current is intaken into the space 8 through other gaps as shown by big arrows B.
On the other hand, if gaps are formed between the cover member 6 and the motor 1, atmosphere is intaken through the gaps, and a dust-containing air current is vigorously jetted out of the gaps between the floor F and the skirt 7. Therefore, the method for simply covering the upper surface side of the buffing pad 4 with the cover member 6 and the skirt 7 in the manner as shown in FIGS. 5 and 6 is not effective for completely preventing the scattering of dusts.
In order to overcome the above-mentioned problem, there have been developed an improved floor polishers. One such example is disclosed by Japanese patent application early laid-open publication No. Sho 62-155823, in which a dust containing air current is guided to a dust collecting device by using a circulation air current generated by a buffing pad rotating at a high speed and a vacuum shroud device but without using an independent vacuum fan. Another such example is disclosed likewise in Japanese patent application early laid-open publication No. Sho 62-16133, in which a vacuum fan adapted to positively perform an intaking of atmosphere and a discharging of a dust-containing air current is disposed within a cover member.
The first-mentioned conventional floor polisher, as shown in FIG. 7, has an air inlet port 6a formed between a pad rotating hub 2 and a cover member 6, and a seal member 7a disposed at a lower edge of a skirt 7 and for intimately attaching to a floor F. When a buffing pad 4 is rotated by the hub 2, air is intaken through the air inlet port 6a and circulated around the buffing pad 4. A dust-containing air current is fed into a dust collecting device (not shown) side such as, for example, a dust collecting bag together with the circulating air current through an outlet port 9 formed on a cover member 6.
On the other hand, the second-mentioned floor polisher, as shown in FIG. 8, has an air inlet port 6a opened up at an upper surface of a cover member 6, a fin 2a serving as a vacuum fan formed on a hub 2, and an outlet port 9 or 10 formed at one end of the cover member 6 and communicating with the same dust collecting device (not shown) as mentioned, a dust-containing air current is positively guided to the outlet port 9 side by means of the rotation of the fin 2a.
However, since the floor F has a lot of irregularities, it is practically impossible to completely intimately contact the skirt 7 with the floor F. Even if the seal member 7a is provided on the skirt 7 as in the first-mentioned floor polisher, gaps are formed at the irregular portion of the floor. Therefore, in the first-mentioned conventional floor polisher, air intaken from the air inlet port 6a is vigorously jetted out of the gaps to scatter dusts. Furthermore, there is as a problem as that the energy of a circulating air current along, which is generated by means of the rotation of the buffing pad 4, is not sufficient to feed a dust-containing air to the dust collecting device side so that the dust is collected therein. Therefore, the outlet port 9 is required to have a sealed box type dust collector provided therein with a structually strong filter so that dust-containing air is positively intaken by a powerful fan or a blower.
On the other hand, in the second-mentioned floor polisher, atmosphere intaken by the fin 2a through the inlet port 6a raises the internal pressure of the internal space 8. Therefore, if gaps are formed between the skirt 7 and the floor F, a dust-containing air is more vigorously jetted out of the gaps and the dust-containing current is not sufficiently flowed to the outlet port 9 side. Therefore, even in this type of floor polisher, in order to prevent the jetting of dust from the skirt 7, it is required that the outlet port 9 or 10 be provided with the same dust collecting device as that of the first-mentioned floor polisher so that the dust-containing air is intaken by a powerful fan or a blower.
There has also been proposed a floor polisher which is formed by removing the inlet port 6a from the second mentioned conventional floor polisher of FIG. 8, gaps between a cover member 6 and a motor 1 being sealed so that an attracting force of a dust collecting device is acted on an outlet port 9 or 10. However, even in this floor polisher, in order to prevent the jetting of dust through the gaps of a skirt 7, it is required that a powerful attracting force by means of a fan or a blower act on the outlet port 9 or 10.
However, in order to rotate the buffing pad 4 at a high speed such as, for example, .phi.510 mm, 2,000 rpm, the pad motor 1 requires an output power of 1.1 KW. In order to prevent the jet-out of dust through the gaps of the skirt at that time, it is required that an attracting force act on the outlet port 9 or 10 with an output power of a motor of 0.75 KW. or more. In this case, the total of the output power required becomes approximately 1.9 KW. This amount is unobtainable from an ordinary plug socket (usually 15A and possibly 20A) at, for example, 100 V and thus the device is impractical as a home appliance or the like. Even in the case of a battery type power supply, such a drawback still exists because the weight and cost are increased as the capacity increases.
The present invention has been accomplished in order to overcome the above-described problems inherent in the prior art.